Detection and organisation of antimicrobial resistance genes in

162 Pages·2006·1.96 MB·English

Institute for Animal Breeding, Federal Agricultural Research Centre
(FAL), Neustadt-Mariensee, Germany

Detection and organisation of
antimicrobial resistance genes in
Bordetella bronchiseptica isolates from pigs

THESIS

Submitted in partial fulfilment of the requirements for the degree

DOCTOR OF PHILOSOPHY (PhD)

at the University of Veterinary Medicine Hannover

by

Kristina Kadlec

from Prague

Hannover 2006.
Supervisor: Prof. Dr. S. Schwarz
Co-Supervisor: Dr. C. Kehrenberg, Ph.D.

Tutorial group: Prof. Dr. S. Schwarz
Prof. Dr. G.-F. Gerlach
Dr. J. Wallmann

Internal evaluation: Prof. Dr. S. Schwarz, Institute for Animal Breeding, Federal
Agricultural Research Centre (FAL), Neustadt-Mariensee
Prof. Dr. G.-F. Gerlach, Institute for Microbiology, Department of
Infectious Diseases, University of Veterinary Medicine Hannover,
Hannover
Dr. J. Wallmann, Federal Office of Consumer Protection and Food
Safety (BVL), Berlin

External evaluation: S. Simjee, Ph.D., Elanco Animal Health, Basingstoke, UK

Examination: 09.11.2006

This work was supported by the H. Wilhelm Schaumann foundation.
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Parts of the thesis have already been published or will be published:

Kadlec K, Wallman J, Kehrenberg C, and Schwarz S.
Antimicrobial susceptibility of Bordetella bronchiseptica from porcine respiratory tract
infections.
Antimicrobial Agents and Chemotherapy (2004) 48, 4903-4906.

Kadlec K, Kehrenberg C, and Schwarz S.
Molecular basis of resistance to trimethoprim, chloramphenicol and sulphonamides in
Bordetella bronchiseptica.
Journal of Antimicrobial Chemotherapy (2005) 56, 485-490.

Kadlec K, Kehrenberg C, and Schwarz S.
tet(A)-mediated tetracycline resistance in porcine Bordetella bronchiseptica isolates is based
on plasmid-borne Tn1721 relics.
Journal of Antimicrobial Chemotherapy (2006) 58, 225-227.

Kadlec K, Kehrenberg C, and Schwarz S.
Efflux-mediated resistance to florfenicol and/or chloramphenicol in Bordetella
bronchiseptica: identification of a novel chloramphenicol exporter.
Journal of Antimicrobial Chemotherapy (2006) in press.

Kadlec K, Wiegand I, Kehrenberg C, and Schwarz S.
Studies on the mechanisms of β-lactam resistance in Bordetella bronchiseptica.
Journal of Antimicrobial Chemotherapy (2006) in press.
Further aspects have been presented at national or international conferences as oral
presentations or as posters:

Kadlec K, Wallman J, Kehrenberg C, and Schwarz S.
Untersuchungen zur in-vitro Empfindlichkeit von porcinen Bordetella bronchiseptica Isolaten
gegenüber antimikrobiellen Wirkstoffen.
Proceedings of the Conference of the Deutsche Veterinärmedizinische Gesellschaft (DVG),
division „Bakteriologie und Mykologie”, Berlin, published in Berliner und Münchener
Tierärztliche Wochenschrift (2004) poster P5, 117, 453.

Kadlec K, Wallman J, Kehrenberg C, and Schwarz S.
In-vitro susceptibility of porcine Bordetella bronchiseptica isolates to antimicrobial agents.
Proceedings of the 56th Conference of the Deutsche Gesellschaft für Hygiene und
Mikrobiologie (DGHM), Münster, published in International Journal of Medical
Microbiology (2004) poster VMP002, 294S1 (Suppl. 39), 221.

Kadlec K, Kehrenberg C, and Schwarz S.
Trimethoprimresistenz bei Bordetella bronchiseptica.
Proceedings of the 26. Congress of the Deutsche Veterinärmedizinische Gesellschaft (DVG),
Berlin (2005) poster 50, 160.

Kadlec K, Kehrenberg C, and Schwarz S.
Cassette-borne trimethoprim resistance among Bordetella bronchiseptica isolates from pigs.
Abstracts of the 45. Interscience Conference on Antimicrobial Agents and Chemotherapy
(ICAAC) of the American Society for Microbiology (ASM), Washington, DC, USA (2005)
poster C1-1045, 74.
Kadlec K, Kehrenberg C, and Schwarz S.
Truncated Tn1721 mediates resistance to tetracycline in porcine Bordetella bronchiseptica
isolates.
Proceedings of the 57th Conference of the Deutsche Gesellschaft für Hygiene und
Mikrobiologie (DGHM), Göttingen, published in Biospectrum (2005) poster KMP002,
Tagungsband 80.

Kadlec K, Wallman J, Kehrenberg C, and Schwarz S.
A four-year survey on in-vitro susceptibility of porcine Bordetella bronchiseptica isolates
from Germany.
Abstracts of the 3rd International Conference on Antimicrobial Agents in Veterinary Medicine
(AAVM), Orlando, FL, USA (2006) poster 13, 89.

Kadlec K, Wiegand I, Kehrenberg C, and Schwarz S.
Genetic basis of ampicillin resistance in Bordetella bronchiseptica.
Abstracts of the 106th General Meeting of the American Society for Microbiology (ASM),
Orlando, FL, USA (2006) poster Z-035, 642.

Kadlec K, Wiegand I, Kehrenberg C, and Schwarz S.
Grundlagen der β-Laktamresistenz bei Bordetella bronchiseptica.
Proceedings of the Conference of the Deutsche Veterinärmedizinische Gesellschaft (DVG),
division „Bakteriologie and Mykologie”, Wetzlar (2006) oral presentation V39, 40.

Kadlec K, Wallman J, Kehrenberg C, and Schwarz S.
In-vitro susceptibility of German Bordetella bronchiseptica isolates from pigs.
Proceedings of the 19th Congress on the International Pig Veterinary Society (IPVS),
Copenhagen, Denmark (2006) poster P31-24, Vol. 2, 457.

Contents

Chapter 1 Introduction 11
1. General considerations 13
2. The respiratory tract pathogen Bordetella bronchiseptica 13
2.1 The genus Bordetella 14
2.2 The species Bordetella bronchiseptica 15
3. Susceptibility testing 17
3.1 Phenotypical susceptibility testing 17
3.2 Genotypical susceptibility testing 20
4. Selected antimicrobial agents 21
4.1 Trimethoprim and sulphonamides 22
4.2 Tetracycline 24
4.3 Phenicols 26
4.4 ß-Lactams 29
5. Horizontal gene transfer of resistance genes 32
5.1 Plasmids 32
5.2 Transposons 33
5.3 Gene cassettes and integrons 34
6. Aims of the present study 36
Chapter 2 Antimicrobial susceptibility of Bordetella bronchiseptica from
porcine respiratory tract infections 45
Chapter 3 Molecular basis of resistance to trimethoprim, chloramphenicol
and sulphonamides in Bordetella bronchiseptica 55
Chapter 4 tet(A)-mediated tetracycline resistance in porcine Bordetella
bronchiseptica isolates is based on plasmid-borne Tn1721 relics 69
Chapter 5 Efflux-mediated resistance to florfenicol and/or chloramphenicol in
Bordetella bronchiseptica: identification of a novel
chloramphenicol exporter 77
Chapter 6 Studies on the mechanisms of ß-lactam resistance in Bordetella
bronchiseptica 93
Chapter 7 General discussion 111
1. General considerations 113
2. Antimicrobial susceptibility of porcine Bordetella bronchiseptica
in comparison to other porcine respiratory tract pathogens 114
2.1 Trimethoprim and sulfamethoxazole/trimethoprim 116
2.2 Tetracyclines 118
2.3 Chloramphenicol and florfenicol 120
2.4 ß-Lactam antibiotics 122
2.5 Macrolides 126
3. Resistance genes in Bordetella bronchiseptica 126
3.1 Trimethoprim and sulphonamide resistance genes 127
3.2 Tetracycline resistance genes 130
3.3 Phenicol resistance genes 133
3.4 ß-Lactam resistance genes 136
4. Localization of resistance genes on mobile genetic elements 138
4.1 Gene cassettes and class 1 integrons 139
4.2 Transposons 140
4.3 Plasmids 141
5. General comparison within the genus Bordetella 141
5.1 B. bronchiseptica isolated from cats 141
5.2 Susceptibility and resistance in Bordetella spp. from human
infections 142
6. General conclusion 143
Chapter 8 Summary 151
Chapter 9 Zusammenfassung 157